Collet



Feb. 20, 1962 G. s. HAvlLAND 3,022,082

COLLET Filed June 21, 1960 2 Sheets-Sheet 1 Feb. 20, 1962 G. s. HAVILAND 3,022,982

, COLLET Filed June 2l. 1960 2 Sheets-Sheet 2 INVENTOR GIRARD S. HAVILAND ATTORNEY United States Patent O 3,022,082 COLLET Girard S. Haviland, West Hartford, Conn., assigner to The Jacobs Manufacturing Company, West Hartford, Conn., a corporation of New Jersey Filed June 21, 1960, Ser. No. 37,708 21 Claims. (Cl. 279-1) This invention relates to collets of the type comprising a plurality of spaced rigid jaws interconnected by resilient means to hold the jaws yieldingly in predetermined spaced relationship. In its broader aspects, the invention contemplates a connection between a plate and a sectional rod comprising a pair of links adapted to be coupled end to end, mechanically interlocked, having shoulders lying on opposite sides of the plate to limit relative movement between the links and plate.

The present invention contemplates improvements over the structures disclosed in the patent to Haviland, No. 2,855,206, dated October 7, 1958. According to the disclosure of this patent, links composed of elastomeric materials are provided with interttng plugs and sockets partaking of a snap action during assembly and separation. In the application of the principles disclosed in the patent, conditions have been encountered under which it becomes highly desirable to increase the resistance of the links to separation under tension. This result has been achieved in accordance with the present invention by providing rigid wall means about a portion of each socket to restrain its expansion and thereby retain the plug within the socket under conditions of greater tension than has been possible heretofore.

A collet conforming to the present invention comprises a plurality of spaced rigid jaws and resilient means interconnecting the jaws to hold them yieldingly in predetermined spaced relationship, with corresponding edges of the jaws engageable with an inclined cam surface in a chuck and opposed peripheral edges of the jaws engageable with a work piece, the resilient means comprising a series of similar resilient links each having ahead and socket and the socket of each link being expansible to receive the head of an adjacent link, characterized by having rigid wall means overlying a portion ofeach socket restraining its expansion. The rigid wall means may be delinedby the jaws themselves by the provision of one or more passages extending through each of the jaws and/ or the rigidV wall means may be defined by an element disposed between adjacent jaws. The resilient means preferably comprises one or more continuous rings composed of individual prefabricated snap links each having a head and an expansible socket.

The invention provides a connection between a plate and a sectional rod, the rod comprising aA pair of links adapted to be coupled end to end and mechanically interlocked, one of the links constituting a rear link having a baseV provided with al shoulder on its front end, a neck projecting forwardly from the base and a plug in front of the neck and defining the front end of the rear link, the plug and base each having a cross section exceeding that of the neck, the other ofthe links constituting a front link having a socket formed in its rear extremity, the socket having an enlarged portion adapted to receive the plug of the rear link, andA having a mouth to receive the frice neck of the rear link, the base of the front link being made of resilient material whereby the plug may be forced into the recess by temporarily widening the mouth, and the latter may be restored to its original size as it approaches the neck, the neck being longer than the mouth thus providing a space between the shoulder on the rear link and the rear extremity of the front link, a plate supported by the sectional rod, the plate having an aperture surrounding a portion of the rear link and being contined laterally between the shoulder and rear extremity of the front link, and rigid wall meansJ embracing a portion of the front link about the socket to restrain separation of the links. y

A collet according to the present invention wherein a plurality of spaced rigid jaws are interconnected by deformable resilient means, may be provided with sealing elements disposed between adjacent jaws extending substantially to their edges. The sealing elements are preferably integral with the interconnecting means assuming the form of separable links. The jaws are preferably disposed in an arc of 360 so as to dene an annulus. The sealing elements disposed between adjacent jaws are preferably deformable and resilient and composed of elastomeric material so as to prevent penetration of cuttings and other foreign matter into the working parts of the collet and the machine with which it is employed.

The invention also contemplates means restraining the links against rotation relative to the jaws. This may be achieved by providing a plurality of sets of separable links extending through a plurality of openings respectively, wherein the links of one set provide restraining means for the links of the other. This restraining means may be disposed between proximate faces of adjacent jaws. In some cases, the links of the two sets may have portions lying between the jaws which are unitary or otherwise interconnected.

A more compiete understanding of the invention will follow from a description of the accompanying drawings wherein:

FIG. 1 is ak plan view depicting a collet embodying the present invention positioned in a chuck;

FIG. 2 is a fragmentary sectional elevation taken along line 2-2 of FIG. 1 on an enlarged scale;

FIG. 3 is a plan view'depicting a sub-assembly of jaws and connecting links adapted to be interconnected with similar sub-assemblies to form a complete collet;`

FIG. 4 isV a sectional elevation on a slightly enlarged scale taken along line 4-4 of FIG. 3;

FIG. 5 is a` sectional elevation taken along line 5-5 of FIG. 4, on an enlarged scale andv depicting a tool employed to assist assembly of the'links;`

FIG. 6 is an elevation depicting a modied. formy of link;

FIG. 7 is an enclv elevation of thelink and jaw depicted in FIG. 6;

FIG. 8 is a sectional elevation takenl along line 8--8 of FiG. 6;

FIG. 9'is a plan View of'another form of collet embodying the' present invention;

FIG. l0 is a sectional elevation on anA enlarged scale taken along line 10-10 of FIG. 9;l

FIG. 11 is a sectional elevationv taken along lineV A--A figuration;

3 of FIG. 10 depicting the collet in its relaxed position when annularly disposed;

FIG. 12 is a sectional elevation taken along line A-A of FIG. 10 depicting the collet under conditions of maximum capacity;

FIG. 13 is a sectional elevation taken along line A-A of FIG. 10 depicting the collet under conditions of minimum capacity; and v FIG. 14 is a sectional elevationtaken along line A--A of FIG. V10 depicting the relaxed positions of the collet elements before they have been assigned an arcuate con- YThe collet 20 depicted in FIGS. 1 and 2 of the drawings comprises a plurality of spaced rigid'jaws 22 interconnected by separable links 24 composed of rubber or other Yelastomeric material. The collet depicted in these figures is of the contracting type wherein the outer edges 26 larger ends or bases 32 of the jaws are supported on the upper surface 34 of a base member 36. A suitable num- 'ber of screws V38 extend through a ange 40 formed on the base member into threaded engagement with tapped Vopenings 40a provided in the pressure member 30. Synchronous actuation of these screws 38 may be achieved in any desired manner such as that disclosed in Stoner application Serial No. 854,432, tiled November 20, 1959, `now Patent No. 2,985,456, or Stoner application Serial No. 35,957, tiled June 14, 1960, now Patent No. 2,985,454. A As best depicted in FIG. 5, each of the links 24 comprises a base 42 at oney end and a plug 44 at the other linterconnected by a neck 46 smaller than either the base or plugand an enlargedbody portion 48 larger` than the lneckin diameter but smaller than the base. A radial vshoulder 50 interconnects the base and body portions and a radial shoulder 52 interconnects the body portion and the neck 46. Extending through the base and into the body portion of each link there isa socket S4 providing an enlarged chamber 56 substantially complementing the head of the plug 44 and a reduced mouth 58 adapted to Vembrace the neck 46 of an adjacent link. Each body portion 48 is received through an opening 60 extending through each jaw between its faces 62 so that when the elements are assembled, each jaw provides rigid wall meansrembracing a portion of a link containing a socket which in turn receives a plug. Under these conditions of assembly, it will become evident that the socket is rendered highly'resistant to deformation so that it will not expand readily to permit retraction of a plug received therein. The assembly of the components is effected by inserting a link 24 .through an opening in one of the jaws until the shoulder 50 of thelink engages one of the faces of the jaw under which conditions the jaw will embrace the body portion 48 so that the neck 46 and enlarged head '44 project beyond the opposite face of the plate. Then the next link or snap link will have its socket 54 applied over the plug of theipreviously assembled link until the Yterminal end of the base of the second link engages the face of the jaw opposite the one engaged by the base of the first link. Then the next jaw will be applied over the body portion 48 of the last applied link and this procedure will be continued'until the prescribedY number of jaws and links have been assembled. To facilitate the assembly, it is desirable to provide sorne way to prevent the entrapment'of air in the sockets as the plugs are inserted. One way of accomplishing this result has been depicted diagrammatically in FIG. wherein a bent wire 64, shown in broken lines is inserted in a socket 54 prior to the introduction of a plug 44 so that as the air in the socket is displaced bythe plug it can escape along the wire. `Whereas bleed openingscould be Vprovided for a similar purpose, their tendency to weaken the links may be'ohjecitionable in some cases. A sub-assemblyrof the links and snap links has been depicted in FIG. 3 and it is understood that such sub-assemblies can be shipped to the ultimate destination whereupon the collet can be assembled.

The base configurations depicted in FIG. 2 prevent rotation of the links relative to the jaws. The basesrof the links of the lower set 66 are polygonal, assuming substantially the form of a square. The bases of the links of the upper set 68 provide a at lower edge 7) for engagement with one of the flat edges of the links of the lower set so that each link of one set will prevent rotation of the abutting link of the other set. The upper edges of the links of the upper set 68 are provided with sealing lips 72 extending substantially to the outer inclined edges 26 of the jaws and sealing lips 74 extending inwardly substantially to the inner work engaging edges 76 of the jaws so that when the collet is assembled in a chuck so as to clamp a work piece 28a, these sealing lips under their deformed condition will exclude cuttings and other foreign material from the lower portions of the collet and chuck. The lips 72 and 74 respectively cooperate with the inclined surface 28 of the pressure member 30 and with the peripheral surface of the work piece 28a to seal over the openings that wouldotherwise exist between the links 24 of the collet and the opposed surfaces Y2,8 and 28a.

A modied form of the snap links has been depicted in FIGS. 6, 7 and 8 wherein the base 78, as best shown in FIG. 8 is slightly wedge shaped so as to have an edge 80 directed towards the inclined edge 26 of the jaw 22 slightly thicker than the edge82 facing in the direction of the work to be engaged. Moreover, each base 78 shown in these figures contains two sockets 54, two body portions 48 and two plugs 44 connected to the body pory tions by two necks 46. By virtue of the wedge shape of the base of each of the links, they adapt themselves to assembly in an annular arrangement without appreciable initial deformation. By forming the plug neck and body portions of two series of links integral with a single base, substantially fewer parts are required and rotation of the links relative to the jaws is prevented.

Whereas the collets thus far described have been depicted as contracting collets adapted to embrace the outer periphery of a work piece, it will be clear that the principles are equally applicable to expanding collets for engagement with the internal wall of a hollow work piece, for an example of which reference is made to the Stoner application Serial No. 35,957, filed .lune 14, 1960, now Patent N0. 2,985,454.

The improved collet construction contemplated by the present application is applicable to the type of collet d1sclosed in the Haviland Patent No. 2,855,206, dated October 7, 1958. This form of the invention has been depicted in FIGS.V9 to 14 inclusive, wherein the jaws 84 and the snap links 86 have been depicted as assuming substantially the same configuration as those of the patent to which reference has been made. Each link, composed of rubber or other elastomeric material comprises a base 88 containing a socket 90 having an enlarged chamber 92 and a reduced mouth 94 receiving the plug 96 and the portion of the neck 98 of an adjacentlink, a portion of whose neck is received through an opening 100 extending through each jaw between its opposite faces 102 and 104. Between each pair 0f jawsY and overlying a portion of each base containing a socket, rigid wall means 106 in the form of a rigid ring is provided so that any tendency of a plug to be withdrawn from a socket under conditions of tension will be restrained.

' In FIG. 14 the parts are shown as assuming relaxed positions prior to the time that the arcuate or annular configuration is imposed. The condition depicted in FIG. 11 is that assumed after the arcuate or annular configuration has been imposed with the elements otherwise in a relaxed condition. After a slight degree of contraction, the parts assume positions such as those depicted in FIG. 12 representing the maximum capacity of the collet.

After further contraction, the parts assume relative postions depicted in FIG. 13 constituting the positions assumed when the collet has its minimum capacity.

In FIG. 14, the annuli 106 providing the rigid wall means have been depicted by broken lines in the positions they assurne with respect to the snap links prior to assembly of the plugs in the sockets or preparatory to separation of the plugs from the sockets. With the annuli 106 in their broken line positions, the elements will be assembled in the manner disclosed in Patent No. 2,855,206. After the elements have been thus assembled, the annuli 106 will be shifted from their broken line positions to their full line positions so as to embrace the bases of the links so as to overlie portions of the sockets contained therein. When tension is imposed upon the chain or rope of links thus assembled, there is a tendency for the socket to become enlarged to permit withdrawal of the head or plug contained therein. This tendency is restrained however by the surrounding annulus 196 in each case so as to avoid accidental separation of the links. When deliberate separation of the links is desired, then of course the annuli can be shifted from their full line positions of FIG. 14 to their broken line positions, whereupon separation can be effected relatively readily.

Here again, the structure disclosed with respect to a contracting collet is readily applicable to an expanding collet as will be recognized by those skilled in the art.

Whereas the embodiments of the -present invention described with reference to the accompanying drawings have been limited in number for purposes of illustration, such variations as will occur to those skilled in the art are contemplated by the appended claims.

I claim:

1. A collet comprising a plurality of spaced rigid jaws and resilient means interconnecting the jaws to hold them yieldingly in predetermined spaced relationship, with corresponding edges of the jaws engageable with an inclined cam surface in a chuck and opposed peripheral edges of the jaws engageable with a work piece, said resilient means comprising a series of similar resilient links each having a head and socket and the socket of each link being expansible to receive the head of an adjacent link, characterized by having rigid wall means overlying a portion of each socket restraining its expansion.

2. A collet according to claim 1 in which said rigid wall means is deiined by said jaws.

3. A collet according to claim l in which said rigid wall means is the wall of a passage extending through each of said jaws.

4. A collet according to claim 1 in which said rigid wall means is defined by an clement disposed between adjacent jaws.

5. A collet comprising a plurality of angularly spaced rigid jaws and resilient means interconnecting said jaws to hold them yieldingly in a predetermined spaced relationship with corresponding edges of the jaws engageable with a conical cam surface in a chuck and opposite edges of said jaws engageable with a work piece, said resilient means comprising a continuous ring composed of individual prefabricated snap links each having a head and an expansible socket, and rigid wall means embracing each link and restraining expansion of its socket for retaining therein the head of an adjacent link.

6. A collet according to claim 5 in which said resilient means comprises a plurality of continuous concentric rings composed of said individual prefabricated snap links.

7. A connection between a plate and a sectional rod, said rod comprising a pair of links adapted to be coupled end to end and mechanically interlocked, one of said links constituting a rear link having a base provided with a shou'der on its front end, a neck projecting forwardly from the base and a plug in front of the neck and defining the front end of the rear link, the plug and base each having a cross sectionexceeding that of the neck, the other of said links constituting a front link having a socket formed in its rear extremity, the socket having an enlarged portion adapted to receive the plug of the rear link, and having a mouth to receive the neck of the rear link, the base of the front link being made of resilient material whereby the plug may be forced into the recess by temporarily widening the mouth, and the latter may be restored to its original size as it approaches the neck, the neck being longer than the month thus providing a space between the shoulder on the rear link and the rear extremity of the front link, a plate supported by the sectional rod, said plate having an aperture surrounding a portion of the rear link and being confined laterally hetween the shoulder and rear extremity of the front link, and rigid wall means embracing a portion of said front link about said socket to restrain separation of said links.

8. A collet comprising a plurality of spaced rigid jaws having corresponding edges engageable with a pressure member and opposed edges engageable with a work piece, deformable resilient means interconnecting said jaws, and sealing elements disposed between adjacent jaws extending from opposite areas of the resilient means substantially to said edges corresponding and opposed.

9. A collet according to claim 8 in which said sealing elements are integral with said interconnecting means.

10. A collet according to claim 8 in which said interconnecting means comprises separable links.

11. A collet according to claim 8 .in which said jaws are disposed in an arc.

12. A collet according to claim 8 in which said jaws are disposed annularly.

13. A collet according to claim 8 in which said sealing elements are deformable and resilient.

14. A collet according to claim 8 in which said sealing elements are elastomeric.

l5. A collet comprising a plurality of spaced rigid jaws having corresponding edges engageable with a pressure member and opposed edges engageable with a work piece, said jaws having opposed faces with openings extending therebetween, separable links extending through said openings and interconnecting said jaws wherein each link has at least one straight edge adapted for abutment with stop means to restrain the link against rotation relative to he jaws.

16. A collet comprising a plurality of spaced rigid jaws having corresponding edges engageable with a pressue member and opposed edges engageable with a work piece, each of said jaws having opposed faces with a plurality of openings extending therebetween, a plurality of sets of links extending through said openings respectively, each of said links having a plug at one end and containing a socket act the other, each plug occupying a socket of an adjacent link, portions of said socket ends substantially fiiling said openings whereby said links are restrained agsinst separation.

17. A collet according to claim 16 in which said opposed faces are substantially plane and said plugs have enlarged ends occupying said sockets intermediate the planes of said faces.

18. A connecting link of elastomeric material having a base at one end and a plug at the other, a neck of smaller cross section than said plug intermediate said plug and base, a body portion having a cross section larger than that of said plug and smaller than that of said base intermediate said neck and base, and a socket substantially complementing said neck and plug extending through said base into said body portion.

19. A joint comprising a member of elastomeric material having a base and a body portion of relatively reduced cross section, a socket extending through said base into said body portion, said socket having an enlarged chamber and a reduced mouth portion, a second member having a body portion, a reduced neck projecting from said body portion and a head having a cross section larger than that of its body portion and smaller than that of said neck, said head occupying said chamber and said neck occupying said reduced mouth. Y Y Y 20. A Y collet comprising a plurality ofV spaced rigid jaws having corresponding edges engageable with a pressure member and opposed edges engageable with a workpiece, said jaws having opposed faces between which extend a plurality of openings, a plurality of separate sets of separable linksfextending through said openings respectively, and the links of each of said sets providing restraining means for engaging the links of another of said 8 sets to prevent rotation of the links relative to each other and to therjaws. y

2l. A collet according to claim '20, wherein the conjugate portions of the links ofthe same set are circular in cross section and the engaging portions of the links for restraining relative rotation thereof are Hat.

References Cited in the le of this patent UNITED STATES PATENTS Greenough Oct. 23, 1956 Haviland Oct. 7, 1958 

